The present invention is directed to a scrap cutter with a feed trough arranged to direct scrap material to cutting knives. The feed trough is arranged to collect and compact the scrap material to be cut and includes an elongated wall forming a side pressure ram in the trough and a cover partially covers the trough.
In the use of scrap shears of the above-mentioned type, there has been a longstanding problem that the scrap material is supplied in a wide range of sizes. In actual use, the scrap material includes smaller pieces of collected scrap and, in addition, bulky or large-sized scrap material with large surfaces, such as pieces obtained when breaking up a ship's hull. As a result, conventional scrap cutters are designed either for small-sized or large-sized scrap material so that the feed trough and cutter opening are adapted to the size of the scrap material being handled.
Cutters for small-sized scrap material normally operated with pre-compaction, that is, scrap is loosely fed into the feed trough and is compacted initially by the trough cover with the possible addition of a side pressure ram extending along the trough for forming a more or less compact mass of the scrap material. Then, with the aid of a conveying ram displaceable in the long direction of the trough, the mass of scrap material is moved stepwise into the cutter opening and is sheared into sections based on the length of each step. To process large-sized scrap material which does not fit into the feed trough, such scrap cutters are unsuitable because the side pressure ram used for the compaction cannot handle large-sized scrap material and, therefore, cannot compact it. As a result, the large-sized scrap material must first be cut up, such as by a flame cutter or the combination of a large-sized scrap cutter and a small-sized scrap cutter must be employed. Since the two different sized scrap materials are supplied in different amounts, it is not possible to attain the efficient use of such cutters.
Special apparatus used for cutting up ships is known combining a primary cutter for dividing the large-sized scrap into long narrow strips which fall into the feed trough of another cutter for further division of the scrap material. Such two-trough cutters operated satisfactorily and, in addition, permit the processing of small-sized scrap material in the second cutter or shears. Such an arrangement, however, is very uneconomical, because the primary cutter often remains unused.
In the German Auslegeschrift No. 24 56 169 is disclosed a cutter with cutting shears arranged along the longitudinal edge of the trough and also on the lower edge of a ram which covers the top of the trough. Offset alongside and above the trough there is a chamber for collecting and compacting the scrap material and an additional displaceable ram compacts the material introduced into this chamber. This compressed body of scrap material is then introduced into the lower trough where it is pushed into a cutter or shears opening. Since the body of scrap material directed into the lower trough may include protruding portions, the edges of the trough and the cooperating ram are provided with shear knives; however, such knives have nothing to do with the shearing operation carried out by the cutter and, therefore, are not explained in any further detail.